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3 years ago

Which of the following numbers must be added to complete the square in the equation below?

Mathematics

2 answers:

OLga [1]3 years ago

4 0

First, take half of the coefficient of 18x then square it.

18 / 2 = 9
9^2 = 81

So, D. 81 is the answer.

Elenna [48]3 years ago

4 0

Answer:

I’m pretty sure the answer is 54

Step-by-step explanation:

The top answer seemed to only do the first step in the equation but if you take 81 and subtract it by -27, the complete answer equals 54. NEVERMIND!!! after reading the question again, 81 is most likely the correct answer.

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Please answer this correctly

jeka57 [31]

Answer:

169.5 yd²

Step-by-step explanation:

See attachment.

In situations like this, ALWAYS (!) make as sketch.

Divide the areas by adding dotted lines on sensible places, and write in the missing numbers for the correct distances.

The only possible difficult one is the triangle, which is the half of a rectangle. So you are dealing with a series of areas of rectangles. That is really easy if you understand what you are doing.

Total area =

area 1 + area 2 + area 3 + area 4

10*4 + 4*7 + 3*13 + (0.5 * 7*17)

40 + 28 + 42 + 59.5

Total area = 169.5 yd²

6 0

3 years ago

A department store is having a 15% off sale on all winter coats. You purchase a winter coat for $275. The department store is lo

sergeinik [125]

$275*.15(15%)=41.25 (this is the amount of the discount)

$275-$41.25=$233.75 (cost of jacket after discount)

$233.75* .0725=$16.946(round to $16.95, this is the amount of the sales tax).

If you want to know the total cost after tax just add $16.95 to the discounted price of $233.75. The price you pay for the jacket is $250.70.

8 0

3 years ago

Read 2 more answers

alex bought 2 dvd's for $28 each. and a dvd player for $85. He gave the cashier $150.00 how much change should alex heve receive

liraira [26]

The answer is $9

28+28+85=141

150-141=$9

8 0

3 years ago

A simple random sample of size nequals81 is obtained from a population with mu equals 83 and sigma equals 27. (a) Describe the

Ivanshal [37]

Answer:

a) $\bar X \sim N (\mu, \frac{\sigma}{\sqrt{n}})$

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

b) $z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

c) $z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

d) $z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

Step-by-step explanation:

For this case we know the following propoertis for the random variable X

$\mu = 83, \sigma = 27$

We select a sample size of n = 81

Part a

Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:

$\bar X \sim N (\mu, \frac{\sigma}{\sqrt{n}})$

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

Part b

We want this probability:

$P(\bar X>89)$

We can use the z score formula given by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And if we find the z score for 89 we got:

$z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

Part c

$P(\bar X$

We can use the z score formula given by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And if we find the z score for 75.65 we got:

$z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

Part d

We want this probability:

$P(79.4 < \bar X < 89.3)$

We find the z scores:

$z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

8 0

3 years ago

Which property is demonstrated below?<br> a + b = b + a

Contact [7]

Answer:

Commutative Property

Step-by-step explanation:

The word "commutative" comes from "commute" or "move around", so the Commutative Property is the one that refers to moving stuff around. For addition, the rule is "a + b = b + a"; in numbers, this means 2 + 3 = 3 + 2. For multiplication, the rule is "ab = ba"; in numbers, this means 2×3 = 3×2.

8 0

3 years ago

Read 2 more answers